Application and Research of Left Bundle Branch-Optimized Cardiac Resynchronization Therapy in Ischemic Cardiomyopathy
Denghong Zhang1,2, Mingjian Lang1, Benjamin Samraj Prakash Earnest2
1Department of Cardiovascular Medicine (Chengdu Institute of Geriatric Diseases), The Fifth People's Hospital Affiliated to Chengdu University of Traditional Chinese Medicine, 611137 Chengdu, Sichuan, China.
Insights
Left bundle branch-optimized cardiac resynchronization therapy (LOT-CRT) improved heart function and reduced QRS duration in patients with ischemic cardiomyopathy. LOT-CRT offers a potential alternative to biventricular pacing when it is ineffective.
Area of Science:
- Cardiology
- Electrophysiology
- Heart Failure Management
Background:
- Ischemic cardiomyopathy is a leading cause of heart failure with reduced ejection fraction.
- Cardiac resynchronization therapy (CRT) is a treatment option for eligible heart failure patients.
- Optimizing CRT delivery, such as with left bundle branch-optimized CRT (LOT-CRT), may improve outcomes.
Purpose of the Study:
- To evaluate the effectiveness of LOT-CRT compared to standard biventricular pacing (BVP) in patients with heart failure and reduced ejection fraction due to ischemic cardiomyopathy.
- To assess key pacing parameters, electrocardiographic changes, and cardiac function indicators between LOT-CRT and BVP groups.
Main Methods:
- A randomized study involving 78 patients with ischemic cardiomyopathy.
- Patients were assigned to either LOT-CRT (n=39) or BVP (n=35).
- Comparison of pacing thresholds, impedance, QRS duration, and cardiac ultrasound parameters at baseline, immediately post-surgery, and at six-month follow-up.
Main Results:
- LOT-CRT group showed significantly shorter QRS duration post-procedure and during follow-up compared to BVP (p < 0.001).
- While both groups showed modest improvements, the LOT-CRT group demonstrated significant improvements in NYHA class, LVEF, and LVEDD at six months (p < 0.001).
- The BVP group exhibited higher pacing thresholds and impedance, along with longer X-ray exposure times.
Conclusions:
- LOT-CRT is a viable alternative for heart failure patients with ischemic cardiomyopathy and left bundle branch block, especially when BVP is not effective.
- LOT-CRT demonstrates superior QRS narrowing and functional improvements compared to BVP in this patient cohort.
- Further research may explore LOT-CRT's long-term efficacy and broader applicability.
Background:
This study aimed to evaluate the effectiveness of left bundle branch-optimized cardiac resynchronization therapy (LOT-CRT) in patients diagnosed with heart failure and reduced ejection fraction due to ischemic cardiomyopathy.
Methods:
A total of 78 patients with ischemic cardiomyopathy who underwent pacemaker implantation at a single center between March 2020 and March 2022 were randomly assigned to two groups based on different pacing methods: LOT-CRT group (n = 39) and biventricular pacing (BVP) group (n = 35). Pacing threshold, impedance, electrocardiogram QRS wave duration during pacing, ventricular pacing ratio during follow-up, and cardiac ultrasound-related indicators were compared immediately after surgery and at the six-month follow-up.
Results:
The two groups were similar regarding baseline characteristics, cardiac ultrasound and magnetic resonance imaging (MRI) parameters, and overall cardiac function. However, the BVP group demonstrated higher pacing thresholds and impedance levels immediately after surgery and at the six-month follow-up (p < 0.001). Moreover, the X-ray exposure time was significantly longer in the BVP group compared to the LOT-CRT group. While no significant differences in QRS duration were observed between the groups preoperatively, the QRS duration in the LOT-CRT group was significantly shorter both immediately after surgery and during follow-up (p < 0.001). No significant differences were found between the groups in terms of the New York Heart Association (NYHA) functional class, left ventricular ejection fraction (LVEF), or left ventricular end-diastolic diameter (LVEDD). Six months post-surgery, both groups showed modest improvements in NYHA class, LVEF, and LVEDD, with the LOT-CRT group demonstrating significant improvements (p < 0.001).
Conclusions:
LOT-CRT may be an alternative treatment for patients with heart failure complicated by left bundle branch block due to ischemic cardiomyopathy in whom BVP is ineffective.
More Related Videos
05:41Left Anterior Descending Coronary Artery Ligation for Ischemia-Reperfusion Research: Model Improvement via Technical Modifications and Quality Control
Published on: December 16, 2022
10:17Real-Time Cardiac Mapping with a Noninvasive Imageless Electrocardiographic Imaging System
Published on: April 11, 2025
Related Concept Videos
01:30Cardiomyopathy II: Dilated Cardiomyopathy
01:29Cardiomyopathy III: Hypertrophic Cardiomyopathy
01:29Cardiomyopathy IV: Restrictive Cardiomyopathy
01:29Cardiomyopathy V: Interprofessional Care